ProxyAddress and UUID don't compareTo()

When we present global views in RELAY, we mix local (UUID) and global (ProxyAddress) addresses. This works fine as both classes implement Address.
However, when we sort them, there's a ClassCastException, because UUID.compareTo(ProxyAddress) fails. ProxyAddress.compareTo(UUID) works.

ProxyAddressTest is the unit test for this.

SOLUTION: add code in UUID.compare() that compares to a ProxyAddress